Table 2.
Unadjusted Incidence Rates of TKA
| Characteristic | Level | n (%) | Number of TKAs |
Years at Risk |
Incidence Rate (IR) |
IR 95% CI |
|---|---|---|---|---|---|---|
| Age, end of follow-up period |
<65 | 664 (35%) |
56 | 4148.9 | 1.3% | 1.0%, 1.8% |
| 65+ | 1251 (65%) |
167 | 7496.1 | 2.2% | 1.9%, 2.6% | |
| Sex | Male | 786 (41%) |
88 | 4729.0 | 1.9% | 1.5%, 2.3% |
| Female | 1129 (59%) |
135 | 6916.0 | 2.0% | 1.7%, 2.3% | |
| Race | White | 1412 (74%) |
191 | 8551.7 | 2.2% | 1.9%, 2.6% |
| Non-White | 502 (26%) |
32 | 3086.8 | 1.0% | 0.7%, 1.5% | |
| Sex–Age | Males <65 | 295 (15%) |
21 | 1848.6 | 1.1% | 0.7%, 1.7% |
| Males 65+ | 491 (26%) |
67 | 2880.4 | 2.3% | 1.8%, 3.0% | |
| Females <65 | 369 (19%) |
35 | 2300.2 | 1.5% | 1.1%, 2.1% | |
| Females 65+ | 760 (40%) |
100 | 4615.7 | 2.2% | 1.8%, 2.6% | |
| Race–Age | Whites <65 | 447 (23%) |
44 | 2803.3 | 1.6% | 1.2%, 2.1% |
| Whites 65+ | 965 (50%) |
147 | 5748.4 | 2.6% | 2.2%, 3.0% | |
| Non-Whites <65 | 217 (11%) |
12 | 1345.6 | 0.9% | 0.5%, 1.6% | |
| Non-Whites 65+ | 285 (15%) |
20 | 1741.2 | 1.1% | 0.7%, 1.8% | |
| Race–Sex | White Males | 633 (33%) |
80 | 3797.7 | 2.1% | 1.7%, 2.6% |
| White Females | 779 (41%) |
111 | 4754.0 | 2.3% | 1.9%, 2.8% | |
| Non-White Males | 152 (8%) |
8 | 924.9 | 0.9% | 0.4%, 1.7% | |
| Non-White Females | 350 (18%) |
24 | 2161.9 | 1.1% | 0.7%, 1.7% | |
| Race–Sex– Age |
White Males <65 | 228 (12%) |
17 | 1441.7 | 1.2% | 0.7%, 1.9% |
| White Males 65+ | 405 (21%) |
63 | 2356.0 | 2.7% | 2.1%, 3.4% | |
| White Females <65 | 219 (11%) |
27 | 1361.6 | 2.0% | 1.4%, 2.9% | |
| White Females 65+ | 560 (29%) |
84 | 3392.4 | 2.5% | 2.0%, 3.1% | |
| Non-White Males <65 | 67 (4%) |
4 | 407.0 | 1.0% | 0.4%, 2.6% | |
| Non-White Males 65+ | 85 (4%) |
4 | 517.9 | 0.8% | 0.3%, 2.1% | |
| Non-White Females <65 | 150 (8%) |
8 | 938.6 | 0.9% | 0.4%, 1.7% | |
| Non-White Females 65+ | 200 (10%) |
16 | 1223.3 | 1.3% | 0.8%, 2.1% | |
| Baseline KL grade |
2 | 970 (51%) |
38 | 6205.7 | 0.6% | 5.3%, 8.0% |
| 3 | 676 (35%) |
95 | 4057.4 | 2.3% | 1.9%, 2.9% | |
| 4 | 269 (14%) |
90 | 1381.9 | 6.5% | 0.4%, 0.8% | |
| Education | High school or less | 364 (19%) |
46 | 2097.7 | 2.2% | 1.6%, 2.9% |
| Some college or more | 1538 (81%) |
175 | 9472.8 | 1.8% | 1.6%, 2.1% | |